Jan 18, 2010

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Used tea leaves can be utilised to produce bio-diesel on a commercial basis

By Alauddin Masood

A Pakistani scientist, Dr. Syed Tajamul Hussain, and his research team at the National Centre for Physics have succeeded in inventing a catalyst for the production of bio-diesel with the help of spent tea leaves. The effort of the Pakistani scientist has opened up new avenues for alternative environment-friendly energy resources.

From one kilogramme of used tea, nano particles help produce 560 ml of bio-diesel, which can be used alone or blended with petro-diesel. If the process is carried out on commercial basis it can be a giant step towards production of alternative energy resources in Pakistan as the country is the third largest importer of tea after UK and China. The annual consumption of tea in Pakistan is estimated to be around 160,000 to 170,000 tons.

Since there is a global ban on the production of bio-diesel from edible products, Dr. Tajamul and his team started research work on used tea leaves and have succeeded for the first time in the world to prepare bio-diesel from used tea leaves. Their research work also showed that the spent tea leaves can be used for the production of alcohol. Earlier, spent coffee had been widely used for the preparation of alcohol, but no one had ever tried to utilise used tea leaves, even in countries like UK and USA where tea users are in large number.

It is now an established fact that urban waste, both organic and inorganic, is a potential valuable resource, which can be used to generate energy, establish new ventures for the recycling of the solid waste, support a host of cottage industries and provide gainful employment to thousands of people. In economic terms, the waste-to-energy production almost costs nothing as it becomes a source of revenue generation through energy, organic fertiliser production, and supply of raw materials to recycling units as well as the cottage industries.

In 2007, the Germans generated almost 280kWh of electricity by using sewage to make methane. A similar experience in the UK estimates that by the end of 2010 about 75 percent of the sewage will be processed to provide about 350,000 British homes with electricity.

In the Philippines, faced with severe opposition from environmentalists, an integrated meat-processing and canning plant succeeded in converting the industrial waste into bio-gas and overcoming the pollution problem in the early 1980s. By doing so, the company not only dealt with the problem of pollution effectively, but it also found a substitute for electricity and liquefied petroleum gas, earning laurels from the nation and the state.

Pakistan generates many hundred thousand tons of waste every year. In Lahore, the old city alone annually generates over 100,000 tons of waste. If the waste of new localities, like Gulberg and Defence Housing Authority and the suburban areas is added to it, the quantity of waste annually generated by the city might increase to about 150,000 tons. Other mega cities, like Karachi, Hyderabad, Faisalabad, Multan, Gujranwala, Peshawar and Quetta also generate colossal amounts of waste.

Presently, the city governments usually burn urban waste or deposit it in landfill project areas. This has been a very costly proposition not only due to high costs involved but also because of multiple negative impacts on human health, the overall environment conditions and contamination of soil as well as ground-water resources. To rectify the damage, the city needs to opt for the waste-to-energy course in place of the costlier Landfill Projects.

In addition to major benefits, like reduction in waste-related diseases, the closed cell utilisation of carbon dioxide ensures minimum damage to the Ozone layer. Against this, the landfill and combustion treatment for the city waste are most damaging for environment and inhabitants.

While resolving the chronic problem of disposing of the piling up dumps in suburban areas and saving huge amounts of money spent on unhealthy and environment-unfriendly landfill projects, the waste recycle route can partly meet the current energy deficit in addition to generating economic activities and new job opportunities. In economic terms, the waste-to-energy production costs almost nothing as it becomes a source of revenue generation through energy, organic fertilizer, production and supply of raw materials to the recycling units as well as the cottage industries.

According to experts, 10-14 thousand tons of waste produced daily in the twin cities of Islamabad and Rawalpindi has the potential to produce 60-70 MWs of energy by generating the methane gas from the organic (wet) waste and then using it for the generation of electricity. If the waste produced by the twin cities of Rawalpindi and Islamabad could be used to produce some 60-70 MWs of energy, imagine the potential that the metropolitan cities of Lahore, Faisalabad, Multan, Karachi, Hyderabad, Peshawar and offer in this regard. The garbage collected in the metropolitan towns of Karachi and Lahore could definitely produce 10-15 times more electricity and organic fertilizer as well as support an equally larger chain of recycling units and cottage industries and job opportunities.

While adoption of waste-to-energy method has reasonable prospects for providing additional source for energy to meet the country's growing need for energy, the adoption of the proposition would also solve the menace of clogged gutters, overflowing drainage and sewerage channels, and piles of litter, which has become a common sight and constant eye-sour in almost all major towns and cities.

Another source for energy production could be the damaged/spoiled fruits or vegetables and corns, which are unfit for human consumption. According to sources, some 40 percent of the total fruits and vegetables produced in Pakistan are lost during harvesting. The damaged fruits and vegetables can also be used for producing low-carbon fuel for cars. The sugar (fructose) found in fruits, such as apples, oranges and dates, can be converted into a fuel, which experiments have revealed, contains far more energy than ethanol.

Likewise, various types of waste products, including polythene bags, can be used to make bio-diesel fuel. Some of the developed countries are heartily embracing bio-fuels as a way of reducing emissions of carbon dioxide and dependency on imported gasoline/oil. Britain has already developed the technology to create bio-diesel from corns, palm oil and a range of other materials, including weeds.

Meanwhile, it is estimated that Pakistan's demand for oil is expected to double by 2015 and quadruple by 2025 as a result of the continuous economic growth. While the thirst of developing countries like Pakistan for energy is increasing, the resources of the present energy exporting countries in the Middle East and the Far East are depleting fast, resulting in the escalation and sudden fluctuation in the price of oil products. This calls for tapping all available resources for the production of energy so as to optimise the indigenous production of this important resource, which is considered vital for the continuous economic growth of the mankind.

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